some posts i found that might relate to your question or lead to some other sources to read -

/u/cleopatra_philopater wrote something about the relationships between ethnic and social classes during Ptolemaic and Roman Egypt: https://www.reddit.com/r/AskHistorians/comments/7awgeo/ptolemaic_and_roman_egypt_a_veritable_ancient/

and also by /u/cleopatra_philopater talks abouts the office of the pharoah during Roman Egypt (and such transitions): https://www.reddit.com/r/AskHistorians/comments/684omb/were_the_trappings_of_the_office_of_pharoah/